The embodiments described herein relate generally to electrical machines and associated electronics, and more particularly, to methods and systems for dissipating heat from the electrical machines.
Certain electrical machines are sometimes referred to as brushless motors. Brushless motors include both brushless AC motors and brushless DC motors and are used in a wide variety of systems operating in a wide variety of industries. Motors commonly include a stator having a plurality of stacked laminations and a central bore for receiving a rotor and associated bearings. A housing encloses the motor and electronics that control the motor. The housing includes a pair of end frames or end caps can be coupled to opposite ends of the stator to facilitate supporting the rotor. Proper radial and axial alignment between the motor components is desired to facilitate providing free rotation of the rotor, preventing excessive eccentricity in an annular air gap between the rotor and the stator and preventing excessive axial rotor thrust.
If not properly dissipated, heat generated by electronics and/or other components during operation of the electrical machine can shorten the life span of various electronics and/or motor components and/or generally result in poor performance of the electrical machine. Cooling fans can be used to facilitate removing heat from the electrical machine into the surrounding environment. Cooling fans, however, should continuously operate in order to create the forced air circulation over the electrical machine. Accordingly, reliability of the electrical machine may become dependent on keeping the cooling fan running so that machine does not overheat and fail, wherein the reliability of the system could be limited to the mean-time-between-failure (MTBF) ratings of the fans.
In other applications, thermal energy generated from the electrical machine can be directed to a heat fin that is either mounted to or an integral part of the electrical machine. Typically, heat fins coupled to the end caps include a plurality of fins exposed to the ambient atmosphere. The fins establish a large surface area that is in contact with the external ambient environment, promoting thermal heat transfer from the heat fin to the environment. Conventional heat fins, however, may not provide enough heat dissipation for some electrical machines and/or electronics enclosures or electronic components which could result in poor performance and/or failure of the electrical machine.